title: Butyrate production in phylogenetically diverse Firmicutes isolated from the chicken caecum.
abstract: Sixteen butyrate-producing bacteria were isolated from the caecal content of chickens and analysed phylogenetically. They did not represent a coherent phylogenetic group, but were allied to four different lineages in the Firmicutes phylum. Fourteen strains appeared to represent novel species, based on a level of ≤ 98.5% 16S rRNA gene sequence similarity towards their nearest validly named neighbours. The highest butyrate concentrations were produced by the strains belonging to clostridial clusters IV and XIVa, clusters which are predominant in the chicken caecal microbiota. In only one of the 16 strains tested, the butyrate kinase operon could be amplified, while the butyryl-CoA:acetate CoA-transferase gene was detected in eight strains belonging to clostridial clusters IV, XIVa and XIVb. None of the clostridial cluster XVI isolates carried this gene based on degenerate PCR analyses. However, another CoA-transferase gene more similar to propionate CoA-transferase was detected in the majority of the clostridial cluster XVI isolates. Since this gene is located directly downstream of the remaining butyrate pathway genes in several human cluster XVI bacteria, it may be involved in butyrate formation in these bacteria. The present study indicates that butyrate producers related to cluster XVI may play a more important role in the chicken gut than in the human gut.
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Research Group Veterinary Public Health and Zoonoses, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium. venessa.eeckhaut@UGent.be
authors.forename: Venessa
authors.initials: V
authors.lastname: Eeckhaut
authors.forename: Filip
authors.initials: F
authors.lastname: Van Immerseel
authors.forename: Siska
authors.initials: S
authors.lastname: Croubels
authors.forename: Siegrid
authors.initials: S
authors.lastname: De Baere
authors.forename: Freddy
authors.initials: F
authors.lastname: Haesebrouck
authors.forename: Richard
authors.initials: R
authors.lastname: Ducatelle
authors.forename: Petra
authors.initials: P
authors.lastname: Louis
authors.forename: Peter
authors.initials: P
authors.lastname: Vandamme
mesh_terms: D000818:Animals; D044822:Biodiversity; D002087:Butyrates / Q000378:metabolism*; D002432:Cecum / Q000382:microbiology*; D002645:Chickens; D016000:Cluster Analysis; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006094:Gram-Positive Bacteria / Q000145:classification* / Q000302:isolation & purification* / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D002087:Butyrates; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S